Hi Tony,
Haven't tried the Recon at the beach only use it for fresh water hunting, We have allot of black sand here in Central California at the local lakes and rivers that only a Pi will get the depth we need for the deeper masked signals.
However, Once at a school was testing to see how deep it would detect a buried nickel. Buried three nickels one at 6", 8" and third at 10' inches. It hit the 6" with ease and even the 8" was a clear signal but not the 10" inch. Re-dug the 10" and rasied it down to 9" inches and the Recon got the 9" buried nickel a clear two-way signal was very pleased.
Now that is with the stock 8" coil, I'm sure it would go allot deeper with the larger coils.
Also want to add I noticed on the ATX video it hit that small nugget with ease and that was using the DD coil, The shot with the Garrett user waving a nugget on his finger across the coil the ATX was able to detect the nugget. Now I know my Recon like the back of my hand and trust me my Recon could never hit something that small, Based from the video shot of the ATX hitting on that small nugget it must have more sensitivity over the Recon and I sure hope it does that alone would make me spring for an ATX.
Going to keep my Recon, Hopefully the ATX coils will work with the Recon may even pick up an ATX if the posts from ATX users come in positive on sensitivity. Would like try the middle size DD coil on the Recon see if that has any effect on sensitivity and Depth, Even compare the two (ATX & Recon) Then share that information with other Recon users.
Take care,
Paul (Ca)